The overall Which? test score is made up of the following star ratings, all determined by our rigorous lab tests.
How we test cooking
These scores indicate how well the slow cooker works. Overall cooking performance gives an indication of how well the slow cooker works regardless of setting, but we also give ratings for the quality of dishes cooked on both the highest and lowest settings. If a slow cooker comes with a 'keep warm' setting, we assess the quality of food that has been left on the setting for an hour. If the slow cooker can accommodate a whole chicken, we check how well it roasts meat, taking into account appearance and crispness, as well as how well the chicken is cooked.
How we test ease of use
Our ease of use rating takes into account how easy each machine is to use overall. We check how straightforward the slow cooker is to use, how clear each of the settings are, ease of storage, ease of cleaning and the ease of following the recipes provided. We also check that the instructions provided are easy to follow and that the appliance will be easy to set up.
How we test build quality
We rate the overall quality of each slow cooker, paying attention to construction, workmanship and materials. If there are gaps, unfinished edges, or flimsy parts, the slow cooker will get a lower rating than models that are more sturdily built.
How we test energy consumption
We work out the energy consumption for slow cookers by measuring the energy consumption (kWh) when cooking on low, high, roasting a chicken and keep warm.